                       :active (complement :done)
                       :done   :done
                       :all    identity)]
-      (filter filter-fn todos)))
+      (filter filter-fn todos))))
 
 
 (reg-sub

;; register-pure-sub provides some macro sugar so you can nominate a very minimal
;; vector of input signals. The 1st function is not needed.
;; Here is the example above rewritten using the sugar.
#_(reg-sub)
  :visible-todos
  :<- [:todos]
  :<- [:showing]

    (count (filter :done todos))))

(reg-sub
  :footer-counts
  :<- [:todos]
  :<- [:completed-count]
  (fn [[todos completed] _]
